The results of implementation of polymer flooding technology in oil fields characterized by high salinity of water are analyzed: Kalamkas (Kazakhstan), Moskudinskoye, Shagirtsko-Gozhanskoye (Russia, Perm Region). It has been established that application of «purely» polymer flooding with standard polyacrylamide is ineffective under these conditions, because there is almost no residual resistance factor for water injected after the slug. An additional feature of polymer flooding is the adsorption of some part of the polymer dissolved in the water by rock, and the forward part of the front of the displacing water turns out to be free of polymer, respectively, with the usual water mobility. An increase in the content of sodium chloride, calcium chloride and other electrolytes from 0,5 to 20% repeatedly increases the adsorption of the polymer on the rock. Adsorption by rocks from mineralized solutions is several times higher than from desalinated waters. With high adsorption, the front of the polymer lags far behind the front of oil displacement by water. The increase of technological efficiency can be achieved due to the combination of polymer flooding with the injection of crosslinked polymer systems, the use of which allows effectively to regulate the flooding process in heterogeneous reservoirs, as evidenced by the experience of work at the Kalamkas field. The results of polymer flooding in the Perm Region show that the technology can be effectively implemented in conditions of low and medium permeability of terrigenous reservoirs characterized by a high salinity of waters with a big content of calcium and magnesium ions due to the use of new types of polymers. As a result of the performed analysis, it is recommended to realize the following arrangement for the subsequent increase of the efficiency of polymer flooding in the Kalamkas field. Research work is required on synthesizing and adapting polymers for the geological and physical conditions for each of the development objects that provide the optimum adsorption range and efficient oil displacement.
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